Source: U.S. Energy Information Administration, Electric Power Monthly, August 2014 edition with June 2014 dataNote: Data include facilities with a net summer capacity of 1 MW and above only.

In the first six months of 2014, 4,350 megawatts (MW) of new utility-scale generating capacity came online, according to preliminary data from the U.S. Energy Information Administration's Electric Power Monthly. Natural gas plants, almost all combined-cycle plants, made up more than half of the additions, while solar plants contributed more than a quarter and wind plants around one-sixth.

Utility-scale capacity additions in the first half of 2014 were 40% less than the capacity additions in the same period last year. Natural gas additions were down by about half, while solar additions were up by nearly 70%. Wind additions in the first half of 2014 were more than double the level in the first half of 2013.

Of the states, Florida added the most capacity (1,210 MW), all of it natural gas combined-cycle capacity. California, with the second-largest level of additions, added just under 1,100 MW, of which about 77% was solar and 21% was wind, with the remaining additions from natural gas and other sources. Utah and Texas combined for another 1,000 MW, nearly all of it natural gas combined-cycle capacity with some solar and wind capacity in Texas.

Source: U.S. Energy Information Administration, Electric Power Monthly, August 2014 edition with June 2014 dataNote: Data include facilities with a net summer capacity of 1 MW and above only.

Fuel-specific highlights include:

Natural gas. Additions of combined-cycle plants (2,179 MW) were up by 60% compared to the same period last year and include the new Riviera plant (1,212 MW) in Florida, expansions at the Lake Side Power Plant (629 MW) in Utah, and the Channel Energy Center (183 MW) and the Deer Park Energy Center (155 MW), both in Texas. Significantly less combustion turbine capacity was added in first-half 2014 (131 MW) compared to the same period last year (3,115 MW).

Solar. Solar additions (1,146 MW) experienced strong year-on-year growth, with nearly 70% more additions in the first half of 2014 than in the same period last year. About three-quarters of this solar capacity was located in California (including the Topaz and Desert Sunlight (Phase 1 and 2) photovoltaic (PV) plants and the Genesis solar thermal plant), with Arizona, Nevada, and Massachusetts making up most of the rest. These data do not include solar capacity additions below 1 MW in size that are typically used in distributed power applications at residential and commercial sites.

Wind. Wind additions (675 MW) were more than double the amount added in the same period last year (329 MW) and were concentrated in California, Nebraska, Michigan, and Minnesota. California's 228 MW of capacity additions came from the Alta Wind X and Alta Wind XI phases of the Alta Wind Energy Center (currently the largest wind farm in the United States at 1,548 MW of total capacity).

Other. In Washington, a 122 MW hydroelectric turbine came online at the Wanapum Dam to replace the 104 MW turbine that was retired in late 2013. The dam is in the middle of a decades-long project to replace all of its turbines (which date back to 1963-64) with new, more efficient turbines one at a time.